The invention concerns an external mirror for motor vehicles, in particular for commercial vehicles, having an improved carrier plate structure.
A substantial problem with external mirrors, particularly in the case of commercial vehicles, is the occurrence of vibration. First, vibration can negatively affect the use of the mirror, and second, vibration of the mirror can lead to damage due to fatigue.
An attempt at a solution to this problem is disclosed in German Patent Publication No. DE-A-40 10 083. In the mirror construction there given, the housing does not exert any carrying function. This carrying function was taken over by means of a holding apparatus onto which a securing means for the affixing of the mirror on a commercial vehicle is fastened. The housing, and at least one mirror pane of the external mirror and an adjustment unit for the positioning of the mirror, are affixed to the holding apparatus. The disadvantage of this is that the carrier plate and the holding apparatus are of separate construction, leading to the danger that the stability of securement of the carrier plate in the holder is reduced. This is especially the case whenxe2x80x94as shown in embodiment of DE-A-40 10 083xe2x80x94the housing is clamped between the holding apparatus and the carrier plate, since here, vibrations can be transferred easily to the carrier plate.
Another external mirror for a motor vehicle is made known by U.S. Pat. No. 4,701,037, wherein a holding arm running to the body and a single piece carrier plate with a molded-on clamp bearing is provided. Where this is concerned, a mirror position adjustment unit is involved onto which a mirror carrier plate is mounted with its mirror pane.
Finally, European Patent Publication No. EP-A-0 590 510 brings into common knowledge an external mirror for commercial vehicles, which exhibits a holder for connection to the body of the vehicle, a carrier plate disposed in a housing, upon which a housing is held and on which, by means of a fastening device the holder is secured, at least one pivotable mirror assembly with a mirror pane is fastened to the carrier plate, and at least one adjustment unit, which is affixed to the carrier plate and is at least bound to the pivoting of said mirror assembly. Experience has shown that even with this mirror design, in actual use, the vibrations are still very large. This is true especially where installation in a truck is involved.
Thus, it is the purpose of the present invention to make available an external mirror for vehicles, especially for commercial vehicles, which is less subject to vibration.
The achievement of this purpose can be accomplished by the features of the claimed invention wherein the carrier plate possesses a base plate and has at least on one side, integral with the base plate, a honeycomb structure incorporated, to decidedly improve the vibratory behavior of an external mirror.
By means of the honeycomb structure, especially when it is on both sides of the base plate, the stability is increased, so that it becomes possible to use plastic instead of metal for the carrier plate, which in turn leads to weight and cost reductions.
In accord with an advantageous embodiment of the invention, the customary hexagonal celled honeycomb can, in various areas of the carrier plate, exhibit different diameters. In this way, the different loadings in various areas of the carrier plate can be taken into consideration. Likewise, it is possible for the heights of the honeycomb cell walls to vary. By means of this variation of the heights of the cell walls, the interactive clamp anchor can be designed as the clamping means integral with the carrier plate.
In accord with a further advantageous embodiment of the invention is a recess for the adjustment device made as one piece with the carrier plate. By means of this recess, the adjustment device is secured by shape forcing, which leads substantially to an improvement of the vibration behavior, that is, strong vibration damping is effected.
In accord with another advantageous embodiment of the invention, the honeycomb structure on the front side, opposite to the honeycomb structure on the back side of the base plate, are mutually offset. This is a further means of increasing the stability and further improves the damping qualities.
In accord with yet another advantageous embodiment of the invention, the carrier plate possesses integral, molded on fastening elements for its securement to a housing base, which latter carries a peripherally circumscribing housing rim, which laterally limits the pivoting motion of the mirror pane.
In the case of an alternative embodiment, the base plate of the carrier plate, the housing base, and the housing rim are designed to be one piece. This simplifies the erection and moreover, the reduced number of the individual components leads to a cost savings and also to an improved stability, which brings in turn an improvement in the vibrational behavior.